Extreme pressure lubricant



Patented June 24, 1941 EXTREME PRESSURE LUBRICANT Henry G. Berger and Darwin E. Badertscher, Woodbury, and Francis M. Seger, Pitman, N. J assignors to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York No Drawing. Application September 25, 1940, Serial No. 358,288

Claims.

This invention is a continuation in part of that disclosed in our copending application Serial No. 177,891, filed December 3, 1937, and relates to the production of extreme pressure lubricants.

As is well known to those familiar with the art, the ordinary type of hydrocarbon lubricant comprised only of a viscous petroleum fraction is incapable of withstanding the enormous pressures encountered between engaged surfaces in various types of machinery such as the hypoid gears used in motor vehicles. This fact has led to the development of the so-called extreme pressure lubricant, which is comprised of a suitable carrying medium such as a mineral oil and a minor proportion of addition agent which will provide or form between the engaged surfaces a lubricant film capable of withstanding these high pressures. Addition agents of the type above referred to are known as extreme pressure agents or E. P. bases, and numerousmaterials have been proposed for such use. Among the various extreme pressure agents which have been produced and which have met with varying degrees of success are organic materials containing sulfur and chlorine. Our present invention relates to this general type of extreme pressure agent.

To demonstrate the efficacy of a material as an extreme pressure agent, various laboratory tests have been developed, such tests employ apparatus having relatively moving engaged surfaces taining a hydroxyl or a metaloxy group.

associated with means for applying the lubricant thereto and associated'with means for varying the' load applied to the engaged surfaces. Typical tests for this purpose which have been accepted by the industry as providing an indication of the performance of lubricants under extreme pressures are the Almen pin test described by Wolf and Mougey, Proc. A. P. I., 1932, pages 118-130, and the S. A. E. test described in S. A. E.

Journal 39, 23-4 (1936).

Our aforesaid copending application SerialNo. 177,891 carries a general disclosure of extreme pressure agents which are obtained by reacting perchloromethylmercaptan with organic com- Perchloromethylmercaptan is a chlorinated substituted sulfurchloride having the formula 08014 or C13CSC1. It can be prepared by the chlorination of carbon disulfide according to the method of Helfrich and Reid (Jour. Amer. Chem. Soc. 43, 591 (1921)). For example, carbon disulfide containing about 0.4 per cent by weight of iodine was chlorinated in the absence of direct sunlight at a temperature maintained below 25 C. until the volume of the reaction mixture had been doubled. This crude reaction product,

which contains carbon tetrachloride and sulfur chlorides in addition to the perchloromethylmercaptan, can be used in the preparation of the lubricants contemplated by this invention, but it is preferable to purify the product by distillation on a water bath at 0., followed by steam distillation. Subsequent vacuum-distillation of the material refined in this manner indicated that the steam-distilled material was practically pure.

As aforesaid, the class of organic compounds containing replaceable hydrogen which is to be reacted with the perchloromethylmercaptan to obtain the extreme pressure agents contemplated herein are those containing a hydroxyl or a metaloxy group. Compounds of this type are the \1 substituted and unsubstituted aromatic alcohols (phenols) and aliphatic alcohols and their metal derivatives. This general class of compounds may be represented by the general formula ROX, in which R. is alkyl, aryl, aralkyl, or alkaryl and X is hydrogen or the hydrogen equivalent of a metal. Typical examples of these compounds are the phenols of the benzene and naphthalene series and the corresponding metal phenates, preferably the alkali metal phenates, and the alcohols with their corresponding alcoholates, preferably the alkali metal alcoholates.

The details in the procedures which may be followed in synthesizing the reaction products contemplated herein may be obtained from the following examples describing the preparation of typical reaction products, in which examples we have also'given extreme pressure lubricant test cal products.

EXAMPLE ONE Reaction product of perchloromethylmercaptan and sodium phenate and the solvent removed at room temperature by means of a vacuum. The product obtained was an oil, and the yield was 42 grams. A mineral oil blend containing 4 per cent of this product failed in the S. A. E. test at a load of 295 pounds with the test machine operating at a speed of 1000 R. P. M., a rubbing ratio of 14.6 to 1 and a loading rate of 8.35 pounds per second. This same oil blend failed the Almen pin test at a load of 29,000 pounds. The blank oil failed in the S. A. E. test at a load of 20 pounds and in the Almen pin test at a load of 3000 pounds.

EXAMPLE Two Reaction product of perchloromethylmercaptan and phenol This reaction mixture was prepared by dissolving 49 grams (0.26 mole) of perchloromethylmercaptan and 50 grams (0.53 mole) of phenol in 200 cc. of benzol. The mixture was refluxed for 8% hours, after which it was washed with Water and with a per cent NaOH solution, and the solvent distilled ofi. The product obtained as residue was a reddish-brown oil which when admixed in the proportion of 4 per cent with a mineral oil described in Example One gave a blend which failed in the S. A. E. test at a load of 320 pounds and passed the Almen pin test at a full load of 30,000

. pounds.

EXAMPLE THREE Sodium ethylate was prepared by dissolving 3 grams of metallic sodium in 40 grams of absolute ethyl alcohol. The sodium ethylate thus obtained was slowly added to 20 grams of perchloromethylmercaptan dissolved in petroleum ether. A vigorous reaction took place, after which the petroleum ether solution was water-washed, filtered, and the solvents distilled oif. The residual product consisted of 16 grams of a yellow liquid having a mild odor. A 4 per cent blend of this product in the mineral oil described in Example One failed in the S. ALE. test at a load of 360 pounds and passed the Almen pin test at a full load ot 30,000 pounds.

EXAMPLE Fons Reaction product of perchloromethylmercaptan and ethylalcohol This reaction mixture was prepared by mixing 38' grams of perchloromethylmercaptan and 100 cc. of 95% ethyl alcohol in a flask connected to a reflux condenser. The mixture warmed up spontaneously to refluxing temperature with evolution of HCl gas. After the reaction subsided water was added and the mixture was extracted with petroleum ether. The ether extract was water washed, filtered and the petroleum ether distilled off. This 1m 26 grams of a pale yellow oil.

A 4% blend of this product in the mineral oil described in the previous examples failed in the S. A. E. test at a load of 315 pounds and passed the Almen pin test at a full load of 30,000 pounds.

EXAMPLE FIVE Reaction product of perchloromethylmercaptan and para-tertiary-amyZ-phenol ing 41 grams (0.25 mole) of p-tertiary-amyl phenol in an equivalent amount of 10% KOH solution and adding the solution thus obtained to a solution of 45 grams (0.24 mole) of perchloromethylmercaptan. in 100 cc. 'of petroleum ether. The solutions were stirred together for one hour starting at room temperature. There was an initial rise of 9 C. in the temperature of the mixture, but this was kept down by waterbath cooling. The petroleum ether layer was then water-washed and the ether'distilled oil to yield 71 grams of the product which was an oil. A 3% blend of this reaction product in mineral oil failed in the S. A. E. test'at a load of pounds and in the Almen pin test at a load of 10,000 pounds.

The reaction products contemplated herein may be used in mineral oil or other suitable carrying medium in amounts varying from 0.5 per cent to 20 per cent to provide a lubricant which will withstand extreme pressure conditions. It is to be understood that while we have described in the foregoing examples certain specific procedural operations and certain-secondary reactants, the invention is not limited to such procedural details or to such reactants as are described above but includes within its scope what ever changes fairly come within the spirit of the appended claims.

We claim:

1. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained byreacting perchloromethyhnercaptan' with an organic compound having the general formula ROX, in which R is selected from the group consisting of alkyl, aryl, alkaryl, and aralkyl radicals and X is selected from the group consisting of hydrogen and the hydrogen equivalent of a metal.

2. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion, from about 0.5 per cent to about 20 per cent, of the product obtained by reacting perchloromethylmercaptan with an organic compound having the general formula ROX, in which R is selected from the group consisting of alkyl, aryl, alkaryl, and aralkyl radicals and X is selected from the group consisting .of hydrogen and the hydrogen equivalent of a metal.

' 3. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained by reacting perchloromethylmercaptan I hydrocarbon lubricating oil and in admixture.

hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained by reacting perchloromethylmercaptan with a metal phenate.

7. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained by reacting perchloromethylrnercaptan with sodium phenate. 8. An extreme pressure lubricant comprising a hydrocarbon lubricating oil and in admixture therewith a minor proportion of the product obtained by reacting perchloromethylmercaptan with an alkyl alcoholate.

9. An extreme pressure lubricant comprising a ate, ethyl alcohol, and para tertiary amyl phenol.

HENRY G. BERGER. DARWIN E. BADERTSCHER. FRANCIS M. SEGER. 

